The present invention relates generally to swimming goggles adapted to be put on a wearer's face for swimming whether it is competitive or not.
Swimming goggles typically comprise a pair of lens units, a pair of lens frame units molded or held integrally with the lens units, a pair of gasket units joined integrally to the lens frame units and having portions adapted to come in contact with the wearer's face, a nose bridge serving to couple respective inner ends of the lens frame units, and a head strap serving to couple respective outer ends of the lens frame units. Numbers of swimming goggles having such typical construction have already been proposed or commercially available and one of them is disclosed in Japanese Unexamined Patent Application Publication No. 2005-160941 (hereinafter referred to as “REFERENCE”).
As will be understood in the light of the swimming goggles disclosed in REFERENCE, a pad unit (corresponding to the gasket unit) is made of an elastic material and a front region of the pad unit is integrally joined to an outer peripheral surface and the rear edge of the lens frame unit so as to cover them while a rear region of the pad unit extends rearward from an inner periphery of the rear edge of the front region and obliquely further extends outward so as to define a region destined to be in contact with the wearer's face. In such construction, a region defined between the rear edge and the region destined to come in contact with the wearer's face is formed on an outer peripheral surface of this region with a concave region having a substantially V- or U-shaped cross-section.
Generally in the swimming goggles disclosed, for example, in REFERENCE, the concave region is necessarily formed in the pad unit since the pad unit must be crooked in order to ensure that the region destined to be held in contact with the wearer's face should elastically held in close contact with the wearer's face although there may be some differences in depth and width of the concave region.
While it is essential for the goggles that the region destined to come in contact with the wearer's face is elastically held in close contact with the wearer's face in order to maintain a complete water-tightness within the goggles, it will be impossible to assure such perfect water-tightness if a pressure at which this region elastically bears against the wearer's face is relatively low. It is obviously supposed that the swimming goggles disclosed in REFERENCE have been designed so as to ensure such contact pressure to a certain degree. However, certain factors such as material, a thickness and cross-sectional shape of the pad unit may often constrain such design intending to maintain the desired contact pressure for a relatively long period. Even if the desired design is achieved, such elastic contact pressure is unavoidably decreased over time due to factors such as deterioration of the material forming the pad unit over time.
With the swimming goggles put on the wearer's face, the region destined to be held in close contact with the wearer's face of the pad unit is elastically deformed so as to come close to the rear edge of the front region of the pad unit as the region destined to be held in close contact with the wearer's face is pushed frontward. Even so, it is not expected that the concave region is perfectly closed. The concave region incompletely closed in this manner will generate a resistance against water flow which is undesirable particularly during competitive swimming.